More and more people are living in cities. This creates both opportunities and challenges which need to be carefully balanced to maintain sustainable development. One of the biggest challenges is the so-called affordability gap which is defined by the global consultancy McKinsey as the difference between the cost of an acceptable standard housing unit and what households can afford to pay using no more than 30 percent of their income.
Many large cities around the world experience this gap. In Ramboll’s Liveable Cities survey, 70 percent of respondents believe that access to housing at reasonable prices has a major or decisive impact on whether a city is attractive, while only 24 percent believe that their municipality provide this.
The biggest difference between what people want and their impression of the municipality’s priorities is in Copenhagen and Aarhus. These two major cities are facing a structural problem with all forecasts indicating that population growth will continue, and more families with children will remain. Despite this, not nearly enough new housing is planned, making house prices go through the roof.
The award winning 8 House in Copenhagen is situated in Ørestad, an area where it is still possible to build affordable housing.
In Copenhagen, for example, the municipality’s own forecast show that the 600,000 people will become close to 800,000 in 2040 – yet there is only new housing planned for around 100,000. Where should the remaining 100,000 live?
New construction and retrofitting Group Executive Director for Buildings in Ramboll Lars Riemann highlights two measures needed to meet the high demand for cheaper housing and mitigate the pressure on prices. One of them is construction in new areas of the city and so-called retrofitting – that is, the renovation of decrepit neighbourhoods, old industrial areas or other areas.
Cities situated close to the sea can use surplus earth from infrastructure projects to build artificial islands and peninsulas. In Copenhagen, earth extracted from the building of the new Copenhagen Metro can be used to construct new housing and businesses on Refshaleøen while at the same time helping create necessary climate protection against storm floods.
In Aarhus, similar initiatives can be undertaken, and the city also has one of Denmark’s best examples of retrofitting in Gellerup.
Used materials as stabiliser
According to the McKinsey report “A Blueprint for Addressing the Global Affordable Housing Challenge”, reducing construction costs and unlocking land supply are the most efficient ways of narrowing the housing affordability gap.
Ramboll is working continuously to reduce construction costs, and we are also a front runner in unlocking land supply.
Materials that cannot be reused in buildings can be used to prepare soil for their construction. A new technology (called UUMA2), developed by Ramboll in collaboration with Aalto University in Finland, is benefiting both the environment and the economy in Vietnam’s capital, Hanoi, among other places.
Soft ground has made some of Hanoi’s central areas uninhabitable, but using cement or ash instead of natural rock as a binder can stabilise the soil and make it fit for development. UUMA2 is also used in Jätkäsaari, a former cargo port on the southern peninsula of Finland’s fast-growing capital, Helsinki.